Simplify Vec allocation in sendmsg after 077d979 removed alignment hacks.

Author: kinetiknz

src/sys/socket/mod.rs

@@ -258,14 +258,12 @@ pub fn sendmsg<'a>(fd: RawFd, iov: &[IoVec<&'a [u8]>], cmsgs: &[ControlMessage<'
         len += cmsg.len();
         capacity += cmsg.space();
     }
-    // Alignment hackery. Note that capacity is guaranteed to be a
-    // multiple of size_t. Note also that the resulting vector claims
-    // to have length == capacity, so it's presently uninitialized.
+    // Note that the resulting vector claims to have length == capacity,
+    // so it's presently uninitialized.
     let mut cmsg_buffer = unsafe {
         let mut vec = Vec::<u8>::with_capacity(len);
-        let ptr = vec.as_mut_ptr();
-        mem::forget(vec);
-        Vec::<u8>::from_raw_parts(ptr as *mut _, len, len)
+        vec.set_len(len);
+        vec
     };
     {
         let mut ptr = &mut cmsg_buffer[..];